Orthopaedic device for correcting abnormal positions of the toes

ABSTRACT

The invention concerns an orthopaedic device for the correction of incorrectly positioned toes, having a fastening provision ( 8   a ) in the region of the big toe, a fastening provision ( 8   b ) in the region of the central foot and a flexible splint ( 9 ), extends between the fastening provisions ( 8   a,    8   b ) along the inner side of the foot, and in which the flexible splint ( 9 ) is formed as a hinged splint, articulated in the direction of flexion and extension of the toe or toes.

FIELD OF THE INVENTION

The invention concerns an orthopaedic device for the correction ofwrongly positioned toes.

BACKGROUND OF THE INVENTION

A foot-binder for the treatment of incorrect positioning of the big toe,for example of hallux valgus, is known from DE 100 34 354 A1. Itfeatures a holder for the big toe, extensible in the foot's longitudinaldirection, and connected at a free end to an annular binding surroundingthe central region of the foot, with the result that a corrective forceacts on the big toe in the direction of the anatomically correct toeposition.

BRIEF SUMMARY OF THE INVENTION

Experience has shown that patients wear such devices only reluctantlyand unreliably, because they are found to be obtrusive, to be a nuisancewhen worn with ordinary shoes, or even, when worn for long periods, tobe tiresome or painful. The success of treatment through the use of thistype of binding is therefore not assured.

A pad splint is known from DE 1 881 215 U1, running along the inner sideof the foot acting as a spring, and having a ring-eye at the toe endthat is used to hold the big toe. At the other end the pad splint iscurved, allowing it to be placed against the heel. This allows a big toeto be brought into the normal position out of an inwardly bent andincorrect toe position. This splint has significant disadvantages. Forinstance it is found by those who wear it to be extremely uncomfortablein use, with the result that it is only very reluctantly worn and theconsequence that the success of the treatment is not ensured.

A device for the treatment of big toes is known from the Germanregistered utility model DE 8 902 545.8 U1, having a stocking with apouch that surrounds the big toe and with a splint running along theinner side of the foot, held in a pocket sewn onto the stocking. Thiskind of device for treating big toes is intended for nocturnal treatmentor when the patient is asleep. Its disadvantage is that the freedom ofmovement of the splinted big toe in the direction of flexion orextension of the big toe is inhibited. This device is therefore notsuitable for long term use. Wearing this device inside a shoe isextremely uncomfortable for a patient, and heavily restricts freedom ofmovement.

Spreading devices are also known, taking the form of a wedge and beingpositioned in the space between the big toe and the second toe, so thatthe big toe is pushed towards the inner side of the foot. Thedisadvantage of these devices is that, in order to exert a force, theysupport themselves against the neighbouring toes, and can thereforecause or encourage incorrect positioning of the neighbouring toes.

The purpose of the invention is to provide a device with which thevalgus displacement of toes, i.e. a displacement in which one or moretoes are displaced toward the outer side of the foot, can be treated. Itshould also be possible to wear the device with comfort, and inparticular without significant impairment of normal activity. This willraise the level of successful treatment in comparison with the currentstate of the art.

This task is performed by an orthopaedic device for the correction ofincorrect toe positioning having a first fastening provision in a regionof a big toe, a second fastening provision in a region of a centralfoot. and a flexible splint, which is held by the fastening provisionsin the regions of the big toe and the central foot and which extendsalong an inner side of the foot wherein the flexible splint is formed asa hinged flexible splint. articulated in a direction of flexion andextension of a toe or toes requiring correction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 A diagrammatic view from below of a first device according to theinvention;

FIG. 2 A diagram of the device according to the invention as in FIG. 1viewed from the inner side of the foot;

FIG. 3 A diagram of a hinged splint of the device according to theinvention shown as a detailed perspective view;

FIG. 4 A diagram of the hinged splint from FIG. 3 as viewed from above;

FIG. 5 A diagrammatic sectional view of the front part of the foot (toesand central foot) of a third embodiment of a device according to theinvention in an extended position;

FIG. 6 A diagrammatic sectional view of the front part of a foot (toesand central foot) of the third embodiment of a device according to theinvention in a bent position;

FIG. 7 A perspective view of a further embodiment of the hinged splintof the device according to the invention;

FIG. 8 The hinged splint in accordance with FIG. 7 with a covered hingemechanism;

FIG. 9 A transverse section through the hinge mechanism of the hingedsplint in accordance with FIG. 7 along the line A-A in FIG. 7;

FIG. 10 A transverse section through the hinge mechanism of the hingedsplint in accordance with FIG. 8 along the line A-A in FIG. 8;

FIG. 11 A longitudinal section through the hinged splint in accordancewith FIG. 8 along the line B-B in FIG. 8;

FIG. 12 A perspective illustration of a further embodiment of the hingedsplint of the device according to the invention;

FIG. 13 A perspective illustration of the hinged splint in accordancewith FIG. 12 with a covered hinge mechanism;

FIG. 14 A transverse section through the hinge mechanism of the hingedsplint in accordance with FIG. 12 along the line A-A;

FIG. 15 A transverse section through the hinge mechanism of the hingedsplint in accordance with FIG. 13 along the line A-A;

FIG. 16 A longitudinal section through the hinged splint in accordancewith FIG. 12 along the line B-B;

FIG. 17 A longitudinal section through the hinged splint in accordancewith FIG. 13 along the line B-B;

FIG. 18 A further embodiment of the hinge of the hinged splint shown ina partial longitudinal section;

FIG. 19 A cross-section through the shank of a hinged splint and theannular binding that belongs to it in the region of the big toe;

FIG. 20 A cross-section through the shank of a hinged splint and anannular binding according to the invention in the region of the centralfoot;

FIG. 21 A second cross-section through the shank of a hinged splint andthe annular binding that belongs to it of the device according to theinvention in the region of the central foot.

BRIEF DESCRIPTION OF THE DRAWINGS

An initial embodiment of the device according to the invention 1(FIG. 1) has an open stocking 2 in the region of the toes or a similarenclosing element for the foot. In the region of the toes the stocking 2has an opening which is edged by a boundary 3. Further, the deviceaccording to the invention 1 includes a holder for the big toe, e.g. atoe pouch 4, which is joined in one piece with the stocking 2 or whichis attached to this stocking 2. The big toe pouch 4 surrounds thecircumference of the big toe, preferably entirely, and is open in theregion of the free end of the toe.

Preferably, however, the big toe pouch 4 is closed at the front, as thishinders the big toe pouch 4 better from slipping relative to the bigtoe.

In the region of the central foot the device according to the invention1 has a first annular binding 5 which surrounds the central foot,preferably entirely, and whose purpose requires it to be connected tothe stocking 2. Advantageously, the first annular binding 5 surroundsthe stocking 2 on the outside in the region of the central foot.

A second annular binding 6 is positioned surrounding the big toe pouch 4in the area of the free end of the big toe, preferably surrounding thecircumference of the big toe completely. The annular bindings 5 and 6are favourably made from a flexible, supple material that resistscircumferential stretching, i.e. in the direction of the perimeter, forexample fabric tape or a non-stretching adhesive tape. In the area ofthe inner side of the foot 7, both the first annular binding 5 and thesecond annular binding 6 are, over a certain area, not joined either tothe stocking 2 or to the big toe pouch 4, so that fastenings/holders 8a, 8 b, e.g. push-in pockets, are formed between the annular bindings 5,6 and the big toe pouch 4 or the stocking 2.

The inner side of the foot 7 is defined as the long side of a foot thatfaces the neighbouring foot. The outer side of the foot is the long sideof the foot opposite the inner side.

A flexible splint 9 extends along the inner side of the foot 7 fromholder 8 b to holder 8 a. The flexible splint 9 is formed as a hingedflexible splint, and has a first hinged splint shank 10 and a secondhinged splint shank 11 which have an articulated connection via a hingemechanism 13 and are thus able to pivot around an axis 12.

The articulated hinge mechanism 13 is arranged in respect of thestocking 2 and of the foot in such a way that the pivoting axis 12corresponds largely to the axis of the main big toe joint in thedirection of flexion and extension 20, which is the natural bendingdirection, i.e. the dorsal and plantar bending direction. Starting fromthe hinge mechanism 13, the first hinged splint shank 10 extends toholder 8 a. Starting again from the hinge mechanism 13, the secondhinged splint shank 11 extends to the second holder 8 b. This means thatthe hinge mechanism 13 is positioned on patients approximately in theregion of the swelling (pseudoexostosis) on the inner side of the foottypical for the hallux-valgus displacement, which often protrudes beyondthe proper contour on the inner side of the foot. Wearing a device 1according to the invention therefore exercises a force F1 acting on theinner side of the foot in the medio-lateral direction. In the region ofthe main big toe joint, a force F2 is exercised through the swelling inthe opposite direction. A supporting force F3 resulting from the forcesF1 and F2 is absorbed in holder 8 b by the first annular binding 5.

In the region of the sole of the foot it is helpful to include a pad 14,in particular a foot-spreading pad, behind the main joints of the toesto provide retrocapital support. This provides supporting alignment ofthe transverse arch, which has an additional beneficial influence oncorrection of the toe displacement.

With the first embodiment in accordance with FIG. 1 with annularbindings 5, 6 it is possible and appropriate to use a normal stocking 2or sock of ordinary woven fabric, since the annular bindings 5, 6, whichresist circumferential stretching, provide sufficient forcetransmission.

In the simplest possible particularly favourable embodiment (FIG. 1 a)the device according to the invention 1 consists merely of the annularbindings 5, 6, the flexible splint 9 and possibly of the pad 14, andthis means that the flexible splint 9 is at least partially in directcontact with the skin of the patient's foot. This extremely simpleembodiment of the device according to the invention 1 has been found tobe particularly effective, since accidental slippage of the device 1relative to the foot of the patient is prevented precisely by theabsence of the intermediate stocking layer. The result is, surprisingly,that omission of the stocking brings increased comfort. Moreover, adevice 1 without a stocking represents the embodiment that is mosteconomical to manufacture. In the embodiment according to FIG. 1 a, theannular bindings 4, 5 are each attached to the associated hinged splintshank 10, 11.

In accordance with a third embodiment of the device according to theinvention (FIGS. 2, 5, 6) the holders 8 a and 8 b are formed frompockets that are sewn or attached in a comparable way to the stocking 2.It is helpful with this embodiment for the stocking to be what is knownas a compression stocking, so that adequate force transmission to thefoot, i.e. an adequately strong transmission of the forces F1 and F3, isensured, even without the annular bindings 5, 6.

The hinge mechanism 13 is in essence constructed from three parts, thefirst hinged splint shank 10, the second hinged splint shank 11, and aconnecting device 14 a for the hinged splint shanks, in particular atubular rivet. The hinged splint shanks 10, 11 each have a free end 15and a hinge end 16. The ends at the hinge 16 have a shape approximatelythat of a universal ball joint, and are designed to correspond to oneanother in such a way that the hinge ends 16 of the hinged splint shanks10, 11 can be engaged with one another and interlock.

The hinge mechanism 13 is formed from the hinge ends 16 which take theform of universal ball joints and are connected by the tubular rivet 14a; it is given high stability in the medio-lateral direction by thedesign of the hinge ends 16 having the form of a universal ball joint.

Moreover the bulge in the hinge mechanism 13 has the additionaladvantage that individual adaptation of the hinge 14 a to the patient'sfoot contour in the region of the main big toe joint is made possible ina simple manner. This is particularly favourable since a round swelling(i.e. what is known as pseudoexostosis) is often found on the foot inthe region of the main big toe joint in the presence of the halluxvalgus displacement. In a particularly favourable manner, the shape,depth, size and diameter of the concave cap can be individually matchedto the patient's foot.

The hinged splint shanks 10, 11, which extend away from the hingemechanism 13, are favourably shaped in cross-section, or in their fullthree-dimensional form, to match the contour of the foot. The hinge ends16 of the hinged splint shanks 10, 11, are not restricted to the shapeof a universal ball joint; rather, any three-dimensional shapes that arerotationally symmetrical about the axis 12 and that correspond to oneanother, in particular the forms of truncated cones or forms with aparabolic cross-section, are suitable.

Metal or plastic are suitable materials for the flexible splint 9 or forthe hinged splint shanks 10, 11, and it has been found that a thin,carbon-fibre reinforced plate is particularly favourable, since it caneasily be moulded through the application of heat, and demonstrates ahigh spring force yet with a low material thickness once it has cooled.

The stiffness of the flexible splint 9 in the medio-lateral direction isfurther increased by a non-constant cross-sectional shape of the shanks10, 11. This means that a device according to the invention having aflexible splint 9 achieves, on the one hand greater comfort, because theflexible splint 9 can be individually adapted to the patients' foot; onthe other hand, an increased spring stiffness in the medio-lateraldirection is achieved, with the result, following primarily from this,that a surprising increase in the success of treatment can be achieved.

A device according to the invention 1 also ensures that on the innerside of the foot, or of the big toe requiring correction, only very thinlayers of material need to be applied, with the result that the deviceaccording to the invention 1 can be worn without significant difficultyin the usual shoe. The freedom of movement of the big toe is in this wayalso not restricted, since it is possible, using the device according tothe invention 1, for the toe to move itself in the natural direction offlexion and extension 20, or for its freedom of movement in thisdirection not to be restricted (cf. FIGS. 5, 6). This makes this device1 particularly suitable for long-term treatment, in the day as well asthe night, since the patient does not experience any significanthindrance as a result of the device 1.

The cross-sectional form of the hinged splint shanks 10, 11 is notconstant. They may, for instance, be bent with constant thickness fromflat material, whereby the shaping is adapted to the individual form ofthe patient's foot. Additionally it is, of course, also possible for thehinged splint shanks 10, 11 to have a lenticular cross-section, inparticular a lenticular form such that the material thickness reducestowards the edges of the hinged splint shanks 10, 11, so that thegeometrical match of the flexible splint 9 to the patient's foot can beindividually further improved.

According to a further embodiment (not illustrated) the orthopaedicdevice according to the invention 1 for the correction of the faultypositioning of more than one neighbouring toe is further developed forinstance through a means of tension being attached to the annularbinding 6 around the big toe in the medio-lateral direction, andaffecting one or more neighbouring toes which may, for instance, also besurrounded by an annular toe binding. In this way the corrective forceof the flexible splint 9 in the medio-lateral direction can betransmitted simply from the big toe to neighbouring toes. Through anappropriate selection of the material thickness for the hinged splintshanks 10, 11, and through suitable selection of the perimeter sectionof these hinged splint shanks 10, 11, and through the easy adaptabilityof the spring tension of the flexible splint 9 in the medio-lateraldirection, it is possible to affect the spring strength in a simple wayand thereby to affect the corrective force F1 for toe position.

Individual adaptation of the corrective force F1 to the specificrequirements of the patient is therefore possible with simple meansavailable in any orthopaedic workshop, such as by adapting the perimetershape of the shanks 10, 11 or changing the cross-section of the shanks10, 11 and/or the hinge mechanism 13.

A further implementation of the hinged splint 9 of the device accordingto the invention 1 (FIG. 7) also has a first hinged splint shank 10 anda second hinged splint shank 11 that have an articulated connection viaa hinge mechanism 13 and are thus able to pivot around an axis 12. Thefirst hinged splint shank 10 is, when the device 1 is positioned in theregion of the patient's big toe, located on the inner side of the foot.

The second hinged splint shank 11 is located in this case in the area ofthe patient's central foot on the inner side of the foot. The firsthinged splint shank 10 has an outer side facing away from the foot 50and an inner side facing towards the foot 51. The first hinged splintshank 10 has a form that is longitudinally and transversely convex butsubstantially flat, with a first longitudinal boundary 52 and a secondlongitudinal boundary 53 as well as a narrow boundary 54. Running nextto the longitudinal boundaries 52, 53 the hinged splint shank 10 hasslot-shaped openings 55 which form a middle stay 56 and an edge stay 57.

The convexity of the hinged splint shank 10 in its longitudinal andtransverse directions are adapted to the anatomical features of a foot.

The annular binding 6, which is attached to the hinged splint shank 10,is provided to fasten the first hinged splint shank 10 to the patient'sbig toe. The annular binding 6 possesses a loop strap 60 and free ends61. The loop strap 60 is used to encircle the big toe of the patient.The free ends 61 are passed from the inside of 51 through the slots 55,reaching through them, passing round the edge stay 57, and has areleasable fastening to an outer face of the loop strap 60. Thisprovides secure fastening of the hinged splint shank 10 to the patient'sbig toe, and permits the size of the loop strap 60 to be adapted to thedifferent sizes of big toes.

The hinge end 16 of the first hinged splint shank 10 features a hingering 70, whose central axis is the pivoting axis 12. The hinge ring 70is favourably joined as one piece with the first hinged splint shank 10.

The hinge ring 70 has an outer side 71, an inner side 72, and an annularstep 73 extending from the inner side 72 some way in the direction ofthe pivoting axis 9.

The second hinged splint shank 11 has an outer face 80 and an inner face81, as well as a first longitudinal boundary 82 and a secondlongitudinal boundary 83 together with a narrow end boundary 84. Thesecond hinged splint shank 11 is primarily formed as a flat body withlongitudinal and transverse convexity, in which the convexities in thelongitudinal and transverse senses are adapted to the anatomicalfeatures in the area of the central foot on the inner side of the foot.The material at the free end 15, and at the longitudinal boundaries 82,83, of the second hinged splint shank 11, like that of the first hingedsplint shank 10, is tapered, so that a cross-section, for instance, willshow a lenticular shape. Approximately parallel to the longitudinalboundaries 82, 83, the second hinged splint shank 11 has slots 85, soforming a middle stay 86 as well as edge stays 87 and intermediate stays88 between the edge stays 87 and the central stay 86.

The hinge end 16 of the second hinged splint shank 11 is favourablyjoined as one piece with the hinged splint shank 11, and takes the formof the hinge disk 90 which, with the hinge ring 70 of the first hingedsplint shank 10, forms the hinge mechanism 13. When the device accordingto the invention is worn by a patient and is attached to the patient+sfoot, the hinge disk 90 faces the skin of the foot and lies against it.The hinge ring 70 is positioned on the outside against the hinge disk90. The hinge disk 90 has, concentric with the annular opening of thehinge ring 70, an annular ridge 91 which extends from the hinge disk 90some way in the direction of the inner region of the hinge ring 70.

The annular ridge 91 sits with little or no free play inside the annularstep 73 of the hinge ring 70, so that the radial relationship of thehinge disk 90 and of the hinge ring 70 to one another is ensured. Forradial localisation of the hinge ring 70 in respect of the hinge disk90, engaging lug segments 92 are moulded on to the annular ridge 91(FIG. 9). These function together with an upper face of the annular step73 so ensuring axial localisation of the hinged splint shanks 10 and 11to one another. The arrangement of the engaging lug segments 92 will bedescribed in more detail in association with FIG. 9. In order to ensurereliable assembly of the hinge mechanism by pushing the hinge ring 70onto the hinge disk 90 and engaging the engaging lugs 92 with theannular step 73 it is favourable for the engaging lugs 92 not to extendaround the full circumference of the annular step 91, so that thematerial elasticity of the hinge ring 70 can act as a spring duringassembly.

According to a particularly favourable embodiment (FIG. 9) the form ofthe hinge disk 90 has a concave cross-section, particularly athree-dimensionally concave form, and has a side 93 that faces intowards the foot and an outer side 94 facing the hinge ring 70, whichalso, corresponding to the inward facing side 93, in particular in theregion outside the annular ridge 91, has a concave form or is partiallyof a concave form. Corresponding to this the hinge ring 70 has an innerside 75 opposite the outer side 71, whose three-dimensional form is suchthat it lies with its surface against the corresponding inner side 93 ofthe hinge disk 90 in the area outside the annular step 91.

In addition to the engaging lugs 92, the annular ridge 91 has a furtherengaging ring 96 or engaging ring segments at its free end, which serveto attach a cap-like closer 100 (compare FIGS. 8, 10).

The closing cap 100 has a means of engagement 101 corresponding to theannular engagement ridge 96, so that the closing cap can be joined toand interlock with the hinge disk 90 or its annular ridge 91. Theclosing cap 100 has an outer face 102 whose three-dimensional form isshaped such that a harmonious transition from the upper face 73 of thehinge ring 70 is ensured. The closing cap 100 serves to close the openhinge mechanism, and thereby to protect it from soiling and/or damage.Favourably the closing cap 100 is located with some free play againstthe inner side 72 of the hinge ring, in order to avoid unwanted noiseand/or excessive friction.

In this way an easily assembled hinge mechanism 13 is easily created,with an exceptionally high ability to accept bending stress whilst atthe same time having low material thickness, and, furthermore, only asmall number of components. Additionally, forming the hinge mechanism 13as an annular hinge means that high bending forces and bending momentscan be introduced to the hinge mechanism 13 without impairing its easeof movement or generating excessive wear. This is primarily due to thelarge supporting width which is made possible by engagement of the lugs92 on the outside with an annular step 72 on the inside of the hingering 70.

This means that the hinged splint 9 primarily consists of just twoindividual parts which provide the function of the splint 9. The closingcap 100 merely has a sealing function, and is not necessary for creationof the hinge.

A particular advantage of forming the hinge ring 13 in this way is thatin the region of the main big toe joint where a pseudoexostosis might bepresent on the patient's foot, the contacting inner side 93 of the hingedisk 90 has a smooth surface, i.e. has no protruding or prominent partsor edges, and this considerably improves comfort. The concave shapetakes the maximum possible pressure off sensitive regions of the foot(pseudoexostosis), thus minimising any pain the patient may feel, sincethe compressive force F₂ is distributed over a wide area. Along thelength (FIG. 11) of the hinged splint 9 care is taken to see that theinner face 51, the inner face 93, and the inner face 81 of the hingedsplint components 10, 11, present a continuous, step-free, smooth curve,which further improves the wearer's comfort. The slots 55 and 85 mayhave teeth 55 a on their side faces which provide grip to prevent theannular bindings 6 that are to be threaded through them from slipping.

The hinged splint shanks 10 and 11 enclose angles α and β respectivelybetween their length and the pivoting axis 12 (compare FIG. 11). Theangles α and β are chosen so that the hinged splint 9 can be placedagainst a patient's foot in such a way that the pivoting axis 12 alignsapproximately with the anatomical joint axis of the main big toe joint,so that when the hinge pivots with the hinged splint shanks 10 and 11attached to the foot, a kinetic pivoting movement of the hinged splint 9largely matching the anatomical conditions of the big toe joint ispermitted. The angles α and β are also chosen in such a way thatcorrection in a direction towards an orthopaedically proper position canbe achieved for a big toe positioned at an angle toward the outer sideof the foot (hallux valgus positioning).

It is of course also within the scope of the invention to select theangles α and β in such a way that it is also possible to correct theless frequently occurring hallux-varus position, i.e. an incorrectpositioning of the toe in which it is shifted towards the inner side ofthe foot away from the normal position. Selection of the angles α and βin accordance with the criteria mentioned above is, of course, possiblefor all the embodiments outlined in this application, and is notrestricted to the embodiments according to FIGS. 7 to 11. Depending onthe severity of the incorrect toe positioning and the desired correctionforce, values in the range between 75° and 115° have been foundeffective for angle α. Within this range, a high proportion of thehallux valgus and hallux varus displacements found are correctable. Inextreme individual cases, it is of course also possible for an angle αoutside this range to be necessary. For the angle β an angle ofapproximately 70° to 110° has been found effective in order to correct ahigh proportion of the typically occurring hallux valgus and/or halluxvarus displacements. It is, of course, also true for the angle β that inspecial cases a larger or smaller value may be selected.

A further embodiment of the hinged splint 9 of the device according tothe invention 1 (FIG. 12) is substantially identical in structure to theembodiment in accordance with FIG. 7, and is based on the same principlefor the correction of displaced toes. The difference between theembodiments in accordance with FIGS. 7 to 11 and the embodiment inaccordance with FIGS. 12 to 17 is merely the hinge mechanism 13, whichhas a somewhat different design. The inner face 72 of the hinge ring 70extends somewhat further in the axial direction. Additionally, theannular ridge 91 of the hinge disk 90 only has the engaging lug segments92, but not the engaging lug segments 96 mounted on top for holding theclosing cap 100.

The closing cap 100 (compare FIG. 13) is inserted into the hinge ring 70in such a way that an external ring wall 105 of the closing cap 100operates in combination with the inner side 72 of the hinge ring 70 insuch a way that the closing cap 100 is fastened to the hinge ring 70 bymeans of a press fit or of an adhesive seating. In this construction itis advantageous if the closing cap 100 does not move relative to thehinge ring 70, so that any abrasive effect against a stocking which mayenclose the hinged splint including the hinge device 16, or with theinside of the shoe, is minimised. This ensures that, between the partialregions 50, 102, 80 of the outer face of the hinged splint 9, norelative movement of the surface sections 80, 100, 70 in the region ofthe hinge mechanism occurs when the hinged splint is operated. A furtherdifference is that the sliding hinge surfaces 94 of the hinge disk 90and the corresponding surface 75 of the hinge ring 70 are formed fromplanar ring surfaces; this represents a simpler construction, with theeffect that the radial guidance of the hinge ring 70 relative to thehinge disk 90 takes place exclusively through an outer face 91 a of theannular ridge 91 and an inner face 73 a of the annular step 73.

It is, of course, also within the scope of the invention to implementthe closing cap 100, according to the embodiment shown in FIGS. 12 to17, on an embodiment of the hinge mechanism 13 according to FIGS. 7 to12. The same applies to the design of the sliding surfaces 75, 94 withrespect to the implementing the principle according to FIGS. 7 to 12 toa hinge mechanism 13 according to FIGS. 13 to 17.

It can be seen from a longitudinal section of the embodiment inaccordance with FIGS. 12 and 13 (FIG. 16), that the effective correctionangle β between the pivoting axis 12 and the effective regions of thehinged splint 9 lying against the foot is 90°.

Further, the hinged splint shanks 10 and 11 have a straightthree-dimensional form in their effective length along their sides 51and 81, which is not particularly closely adapted to the anatomicalcurve of the foot or of the big toe. Thus this kind of embodiment of thehinged splint represents a simplified form of the hinged splint 9 whichis nevertheless effective for a large number of the cases requiringtreatment. The corresponding angles α and β in FIG. 11 are shown, forthe sake of simplicity, between the pivot axis 12 and the outline, whichdoes not however make a great difference. What is meant in any case isthe effective angle between a conceptual effective axis of the hingedsplint shank and the pivot axis 12, whereby inserting such an effectiveaxis on the drawing in the case of an entirely free-form hinged splintadapted to the anatomical features of the human foot in accordance withFIG. 11 can only be a rough estimate. It is therefore clear that theangles α and β in accordance with FIG. 16 and the angles α and β inaccordance with FIG. 11 are in principle the same effective angles.

In the longitudinal section representation according to FIG. 17, theembodiment of the hinged splint 9 in accordance with FIGS. 12 and 13 isillustrated with a closing cap 100 applied.

A further embodiment of the hinge mechanism 13 (FIG. 18) of the hingedsplint 9 of the device according to the invention 1 is also constructedas what is called a sliding annular hinge with a hinge disk 90 and ahinge ring 70. The hinge ring 90 has an inner side 93 facing the skin ofthe foot and, opposite this, an outer side 94. From the outer face 94,an annular ridge 91, which has an outer annular ridge surface 91 a,extends some way in a direction away from the patient's foot.

The outer annular ridge surface 91 a serves to guide the hinge ring 70radially, and operates with little or no play together with the innerhinge ring face 73 a.

The hinge disk 90 is, as in the foregoing embodiment, favourably concavein shape, in particular having a three-dimensionally concave form, andhas, outside the annular ridge 91, a partial region of the outer side 94which serves as a sliding hinge surface and which operates together witha corresponding sliding hinge surface 78 of the hinge ring 70. Thesliding hinge surfaces are concave in shape. In the embodiment accordingto FIG. 18 the height of the annular step 73 of the hinge ring 70 isselected in such a way that one upper surface 73 b of the annular stepis flush with an upper surface 91 b of the annular ridge 91, orprotrudes somewhat beyond it. In this way the interaction of the annularridge 91 and the hinge ring 70 with surfaces 91 a and 73 a ensuresradial guidance of the hinged splint shanks 10, 11. The axial guidanceof the hinged splint shanks 10, 11 with respect to one another isensured in one direction by the sliding surface 78 and its correspondingsliding surface section on the outside 94 of the hinge disk 90. In thedirection opposite to this direction, the axial positioning of thehinged splint shanks 10, 11, or of the hinge ring relative to the hingedisk 90 is provided as explained below.

The closing cap 100 is, in addition to its function of closing the hingemechanism 13, also formed as an axial bearing. The closing cap 100 has aclosing cap body 103, which, as in the embodiments described above,substantially covers the hinge mechanism 13, thereby protecting it fromsoiling. From the closing cap body 103 an annular ridge 105 extendsopposite to the upper side 102, whose diameter is chosen such that itcan be inserted inside the annular ridge 91 of the hinge disk 90 in thespace surrounded by the annular ridge 91.

Outside the annular ridge 105 the closing cap 100 is surrounded by aprojection 106 whose radial dimension is such that it protrudes to someextent beyond the annular ridge 91 and lies on the upper side of theannular step 73 b with little or no axial play. In this way, anunderside 107 of the annular projection 106, which operates togetherwith the upper side 73 b of the annular step 73, serves as an axialabutment. In order for such a hinge construction to be able to acceptthe high bending forces that the hinged splint 9 must generate, withoutdamage and over long periods, the closing cap 100 is advantageouslyglued or otherwise securely fastened to the hinge disk or to its annularridge 91 at one or more of their contact surfaces.

This hinge mechanism 9 also has the special advantage that the surfaces93 that lie against particularly sensitive regions of the foot, e.g. inthe region of a pseudoexostosis, are flat, i.e. there are neitherprojections nor hollows that could irritate those regions of the skin.Furthermore the hinge design according to FIG. 18 has a particularlyhigh bending stiffness, and does not easily come apart even if thesplint is excessively bent. This means that if improperly handled bypatients e.g. by being twisted, excessively bent or similarly treated,the two hinged splint shanks 10, 11 will not come apart.

Plastic, in particular plastic that is impact-resistant andnon-irritating to the skin, e.g. of the polycarbonate class, has beenfound to be favourable material for the hinged splints.

The fastening of the hinged splint 9 to the patient's foot and therouting or threading of the annular bindings 5, 6 through the slots 55,85 of the hinged splint 9 are described in more detail below with theaid of FIGS. 19 to 21.

The annular binding 6 in the region of the big toe (FIG. 19) serves as afastening mechanism, and has both a loop strap 60 and free ends 61. Theloop strap 60 together with the first hinged splint shank 10 encloses aninner region 62 where the patient's toe is located. The free ends 61 arepassed from the inside 51 through the slots 55 and round the edge stay57, enclosing it. As a result, the free end 61 of the annular binding 6is positioned close to the hinged splint shank 10 on the outside withthe loop strap 60. The free end 61 is favourably attached with a velcrofastener 63 to the outside of the loop strap so that it can easily bedetached. This type of fastening of the free end 61 can be applied toboth free ends 61 of the annular binding 6. Nevertheless, in some casesit is also favourable for one free end 61 to be passed around one edgestay 57 and, if appropriate, sewn permanently to the loop strap 60, andfor only one other free end 61 to be joined with a velcro fastener orsimilar, comparable easily-released surface fastening to the loop strap60.

The annular binding 5 serves as a fastening mechanism and as a bindingto support and realign the transverse arch of the foot, and is also bejoined with the second hinged splint shank 11 forming a loop strap 50.The annular binding 5 also has free ends 51. One free end 51 is passedfrom the inside 81 through the first slot 85 close to the underside ofthe foot, lying on the outside of the first intermediate stay 88,passing through the second slot 85 from the outside 80, lying on theinside 81 in the region of the middle stay 86 and passing through thenext slot 85 from the inside 81 through to the outside, lying on thesecond intermediate stay 88 on the outside and passing through the lastslot 85 from the outside 80 to the inside.

The remaining free end 51 is positioned, for example, against the instepof the foot. The remaining part of the annular binding 5, which is notinvolved in threading through the second hinged splint shank 11, ispassed around the patient's foot to the underside of the foot and thetop of the foot, overlaps the second hinged splint shank 11 in theregion of the slots 85, and is fastened to the second free end 51 on theoutside of the loop strap 50. Velcro fasteners, in particular hookfasteners or mushroom velcro fasteners 53, have been found effective asa means of fastening. In this method of threading the annular binding 5through the second hinged splint shank 11 and then wrapping around theentire central foot is particularly advantageous, since the edgeboundaries 83 of the hinged splint shank 11 do not lie directly againstthe skin of the foot, thus avoiding the formation of pressure points.

In certain cases it can also be favourable for the two centrallypositioned slots 85 to be omitted, and for the annular binding 5 simplyto be passed through the outermost slots 85 without taking the patharound the middle stay 86. This embodiment has the advantage that in theregion of the hinged splint shank 11, inasmuch as this lies against thefoot, there are fewer level variations and therefore fewer pressurepoints on the foot. In the region of the internal space 52 surrounded bythe loop strap 50, in which the central foot region of the patient islocated, it is advantageous to attach the pad 14 to the annular binding5 also using Velcro fasteners 53 in the area of the underside of thepatient's foot.

A further advantage of this method of threading the annular binding 5 isthat it is not necessary to thread through the openings 85 of the hingedsplint shank 11 in order to apply the splint 9, but merely for theready-threaded annular binding to be placed around the foot and to befirmly tied and fastened underneath the foot. This makes it possible toeasily adjust or readjust the tightness of the annular binding 5, andthereby its corrective effect on the transverse arch of the patient'sfoot in the region of the central foot.

A further embodiment of the threading of the annular binding 5 throughthe second hinged splint shank 11 (according to FIG. 5), is carried outby passing a first free end through a slot 85 from the inside 81 andaround the edge stay 87 in the region of the underside of the foot, andfor it to be joined on the outside to the loop strap in the region ofthe underside of the foot by means of connecting elements 53. The otherfree end 51 is passed in the region of the top of the foot from theinside 81 through a slot 85 at the edge to the outside, lies on theoutside of the first intermediate stay 88 and is passed through afurther slot 85 in the direction towards the inside 81, lies on theinside of the middle stay 86, passes round this through a furtheropening 85 and is passed outside in the direction towards the top of thefoot, partially overlapping the hinged splint shank 11. The free end 51can in this way be fastened by means of connecting elements 53 to theoutside to the loop strap 50.

The annular binding routing in accordance with FIG. 21 has the advantagethat the free ends will always be located at the outside of the loopstrap 50, so that steps in the thickness of the material plus theconnecting elements 51 are not created at the foot, thus avoidingpressure points at the foot. With this embodiment also it is of coursepossible for free ends at the top of the foot simply to be passedthrough one edge slot 85, so that it passes round the edge stay 87 andcan be fastened at the outside to the loop body 50.

In this case the threading or looping of the annular binding 5corresponds to that of annular binding 6 in the region of the big toe.In this embodiment again, it is possible for the pad 14 to be fastened,particularly in a manner that is easily released, using Velcro fasteners53 to an inner side of the loop body 50 in the region of the underneathof the foot.

The non-rigid and, to a limited extent, floating attachment of thedevice 1 to the inner side of the foot has the advantage that the device1 can adapt individually to the anatomical conditions, i.e., forinstance, that the pivoting axis 12 of the hinged splint 9 can alignitself automatically and continuously to the anatomical joint axis ofthe main big toe joint after the device 1 has been attached.

1. An orthopaedic device for the correction of wrongly positioned toes,comprising: a first fastening provision for placement in a region of abig toe, a second fastening provision for placement in a region of acentral foot, and a flexible splint, which is held by the first andsecond fastening provisions and which is adapted to extend along aninner side of the foot wherein the flexible splint is formed as a hingedflexible splint, articulated in a direction of flexion and extension ofa toe or toes requiring correction, the flexible splint including ahinge mechanism adapted to be positioned on the main big toe joint andhaving a pivot axis that corresponds approximately to the joint axis ofthe main big toe joint in the direction of flexion and extension.
 2. Adevice in accordance with claim 1 wherein the device includes a stockingfor a foot that carries the first and second fastening provisions andthe flexible splint.
 3. A device in accordance with claim 2, wherein thestocking is open in a region of the toes.
 4. A device in accordance withclaim 2, wherein the device incorporates a holder for the big toe thatis joined as one piece with the stocking or that is attached to thestocking.
 5. A device in accordance with claim 4, wherein the holder forthe big toe is adapted to fully enclose the big toe and which is open orclosed at a free toe end.
 6. A device in accordance with claim 2,wherein the device incorporates an annular binding for placement in theregion of the central foot for entirely surrounding the central foot andconnected to the stocking.
 7. A device in accordance with claim 6,wherein a first annular binding surrounds the outside of the stocking inthe region of the central foot.
 8. A device in accordance with claim 7,wherein a second annular binding fully encloses the holder for the bigtoe in the region of the free end of the big toe, and is adapted tofully surround the big toe.
 9. A device in accordance with claim 8,wherein the first and second annular bindings are formed of a flexible,supple material resistant to tension in the circumferential direction.10. A device in accordance with claim 8, wherein in the region of oneinner side of the foot both the first annular binding and the secondannular binding in some areas are not joined to the stocking or to theholder for the big toe, so that between the first and second annularbindings and the holder for the big toe or the stocking, the first andsecond fastening provisions are formed.
 11. A device in accordance withclaim 10, wherein the fastening provisions consist of push-in pockets.12. A device in accordance with claim 10, wherein the fasteningprovisions are formed as pouches sewn onto the stocking or fixed in someother way.
 13. A device in accordance with claim 6, wherein the annularbinding is joined to hinged splint shanks of the flexible splint.
 14. Adevice in accordance with claim 6, wherein the annular bindingincorporates loop straps and free ends.
 15. A device in accordance withclaim 2, wherein the stocking is a compression stocking.
 16. A device inaccordance with claim 1, wherein the flexible splint has hinged splintshanks whose three-dimensional form may or may not be planar.
 17. Adevice in accordance with claim 16, wherein the hinged splint shankshave a lenticular cross-section.
 18. A device in accordance with claim16, wherein the hinged splint shanks each have a free end and a hingeend at the hinge mechanism.
 19. A device in accordance with claim 18,wherein the hinge ends near the hinge mechanism have a three-dimensionalform, and are formed so as to correspond to each other in such a waythat the hinge end of one of the hinged splint shanks can be insertedinto the hinge end of an other of the hinged split shanks and interlock.20. A device in accordance with claim 18, wherein the hinge ends of thehinged splint shanks have a form corresponding to one another withrotational symmetry about a pivot axis that corresponds approximately tothe joint axis of the main big toe in the direction of flexion andextension.
 21. A device in accordance with claim 16, wherein the hingedsplint shanks are manufactured from thin, carbon-fibre reinforced plate.22. A device in accordance with claim 16, wherein the hinged splintshanks have a three-dimensional form substantially that of a plate,longitudinally and laterally convex, having a first longitudinalboundary and a second longitudinal boundary as well as a narrowboundary.
 23. A device in accordance with claim 22, wherein in theregion of the longitudinal boundaries, and parallel to them, slots areprovided, with the effect that a central stay, edge stays andintermediate stays are formed.
 24. A device in accordance with claim 22,wherein the convexities of the hinged splint shanks are longitudinallyand transversely adapted to the anatomical features of a foot.
 25. Adevice in accordance with claim 1, wherein the flexible splintincorporates a first hinged splint shank and a second hinged splintshank which are able to pivot around an axis having an articulatedconnection through a hinge mechanism.
 26. A device in accordance withclaim 25, wherein the first hinged splint shank extends from the hingemechanism to the first fastening provision and the second hinged splintshank extends to the second fastening provision.
 27. A device inaccordance with claim 25, wherein the hinge mechanism consistsessentially of the first hinged splint shank, the second hinged splintshank and a hinged splint shank connecting mechanism.
 28. A device inaccordance with claim 25, wherein the hinged splint shanks and the hingemechanism have a three-dimensional form adapted to the shape of thepatient's foot.
 29. A device in accordance with claim 25, wherein thehinge mechanism is formed as an annular hinge with a hinge ring and ahinge disk.
 30. A device in accordance with claim 29, wherein the hingering is joined as one piece with the first hinged splint shank and/orthe hinge disk is joined as one piece with the second hinged splintshank.
 31. A device in accordance with claim 29, wherein an annularridge is moulded onto the hinge disk, and this operates in combinationwith the hinge ring with the result that radial relationship of thehinge disk and of the hinge ring is maintained.
 32. A device inaccordance with claim 29, wherein for axial positioning of the hingering relative to the hinge disk engaging elements that operate togetherwith a step, in particular an annular step, are provided.
 33. A devicein accordance with claim 25, wherein the hinged splint shanks have amaterial thickness that tapers towards each of the edge regions.
 34. Adevice in accordance with claim 25, wherein the hinge mechanism iscovered by a closing cap.
 35. A device in accordance with claim 34,wherein the closing cap is connected to the hinged splint by engagingdevices.
 36. A device in accordance with claim 34, wherein the closingcap is joined to the first hinged splint shank.
 37. A device inaccordance with claim 34, wherein the closing cap is joined to thesecond hinged splint shank.
 38. A device in accordance with claim 34,wherein the closing cap is formed as an axial bearing.
 39. A device inaccordance with claim 25, wherein the longitudinal extension of thehinged splint shanks enclose an angle α and β with the pivot axis, andwhere the angles α and β are chosen in such a way that the hinged splintcan be placed against a patient's foot in such a way that the pivot axisof the hinge mechanism is approximately in line with the anatomicaljoint axis of the main big toe joint.
 40. A device in accordance withclaim 39, wherein the angle α is between 75° and 115°.
 41. A device inaccordance with claim 39, wherein the angle β is between about 70° and110°.
 42. A device in accordance with claim 25, wherein annular bindingsfor placement around the central foot and around the big toe of thepatient are positioned or threaded through the hinged splint shankswithout creating steps.
 43. A device in accordance with claim 42,wherein the annular bindings are fully threaded into the second hingedsplint shank prior to application to the patient's foot.
 44. A device inaccordance with claim 25, wherein the device is not fixed rigidly to thefoot, so that when worn the device can adapt the position of the hingeaxis of the pivot mechanism individually to the anatomical features ofthe patient's foot.
 45. A device in accordance with claim 1, wherein afoot-spreading pad is adapted to be used in an area of the sole of thefoot behind the main joints of the toes for retrocapital support of thecentral foot.
 46. A device in accordance with claim 1, wherein a forceF1 can be exerted on the big toe in the direction of the inner side ofthe foot by the flexible splint for lateral correction of the big toe.47. A device in accordance with claim 46, wherein there is a provisionfor exerting the force F1 on one or more neighbouring toes.
 48. A deviceaccording to claim 47, wherein the provision consists of a toe holderfor joining the big toe to one or more neighbouring toes of a foot. 49.A device in accordance with claim 1, wherein the surface regions of theflexible splint adapted to lie along the patient's foot are smooth. 50.A device in accordance with claim 1, wherein the flexible splint ismanufactured from a plastic resistant to impact and not irritating tothe skin.
 51. A device in accordance with Claim 1, wherein the flexiblesplint comprises a first splint shank hinge end and a second splintshank with a second splint shank hinge end, and one of the first splintshank hinge end and the second splint shank hinge end comprises a firstshape that is inserted into and interlocked with a second shape of another of the first splint shank hinge end and the second splint shankhinge end.